Jack



` Dec. 30, l924- 1,520,785

E. THOMPSON ET AL JACK VZyf Filed May 5, 1924 Mam/ssc s Patented Dec. 30, 1924.

UNITED STATES ELVIN THOMPSON AND LEO L. DIE-BEL, OF ALLIANCE, OHIO.

J ACK.

Application filed May 5,

To all whom t may concern.'

Be it known that we, ELviN THOMPSON and Lito L. Dinner., citizens of the United States, residing at Alliance, in the county of Stark and State of Ohio, have invented certain new and useful Improvements in Jacks, of which the following is a specification.

This invention relates to lifting mechanisms and the primary object of the invention is to provide a vehicle jack of a small and compact structure which can be extended a relatively great distance for permitting the lifting of the vehicle to a maximum height with a minimum amount of en ergy or exertion.

Another object of the invention is to provide a. vehicle jack embodying stationary supporting rack bars, a main movable rack bar, a traveling casing mounted upon the Stationary rack bars, and novel means for synchronously operating the casing or the stationary rack bars and sliding the main rack bar within the casing.

A still further object of the invention is to provide an improved jack of the ahove character, which will be durable and e'icient in use, one that will be simple and easy to manufacture, and one which can be placed upon the market at a reasonable cost.

Vith these and other objects in View, the invention consists in the novel construe tion, arrangement and formation of parts, as will be hereinafter more specifically described, claiined and illustrated in the accompanying drawings, in which drawings:

Figure 1 is a side elevation of the improved jack showing parts thereof broken away and in section,

Figure 2 is a vertical section through the jack taken on the line 2-2 of Figure 1,

Figure 3 is a detailed vert-ical section taken on the line 3-3 of Figure t,

Figure 4 is a section similar to Figure 2 illustrating the main lifting rack bar and the housing in their partially raised posilion, and

Figure 5 is an enlarged fragmentary section showing the pin and groove connection between the rack bars and the housing for limiting the movement between the rack bars and housing or casing.

Referring to the drawings in detail, wherein similar reference characters designate corresponding parts throughout the 1924. Serial No. 711,258.

base plate formed of any desired material, such as cast iron or the like. The up per face of the base block 10 is provided at spaced points with a pair of sockets 11 and 12 which are adapted to receive the lower end of the supporting rack bars 13 and 141. As shown these rack bars 13 and le are dis posed in spaced parallel relation and are provided with rack teeth on one edge of the same. These supporting rack bars 13 and 14 are adapted to slidably receive the casing 15 which is divided by longitudinally extending spaced partition walls 1G into side 4guides 17 and 18 for receiving the supporting rack bars 13 and 1a and into an intermediate relatively large guide 19 for receiving the main lifting rack 20. This main lifting rack 20 is provided at its upper end with a head 21 which is preferably serrated or otherwise roughened to forni means for engaging the work to be lifted. One side of the casing 15 has formed thereon in any desired way housings 22 and A3 for receiving upper and lower worm wheels 24; and 25. These worm wheels 2st and 25 are keyed or otherwise secured respectively to upper and lower driven shafts 26 and 27. These driven shafts 26 and 27 are arranged at right angles to the main drive shaft 28 which extends forwardly from the jack A. This main drive or operating shaft 28 has formed thereon or secured thereto in any desired way a worm 29 which is adapted to mesh with the worm wheels 24 and 25.

The upper shaft 26 has formed thereon or secured thereto in any desired way a pinion 30 which is adapted to mesh with the main lifting rack bar 20.

The lower shaft 27 has formed thereon or otherwise secured thereto at spaced points pinions 31 which l'it in the guide ways 17 and 18 and mesh with the supporting rack bars 13 and 14:.

The outer end of the operating or drive shaft 28 is polygonal shaped in cross section as at 32 for the reception of an operating crank or the like not shown), whereby the said shaft can be conveniently operated by the hand of the operator.

In order to limit the upward movement of the main lifting rack bar 2() a pin 33 is secured to the lower end of the said rack bar 20 and is slidably mounted in a guide groove 34% formed in the housing 15. It is obvious that when the main lifting rack bar 2O is raised to its extreme uppermost position that the pin 33 will be at the end of the groove 34 and in engagement with the end wall thereof and thus effectively prevent further raising of the rack bar and prevent the rack bar from coming out of mesh with its pinion.

In operation of the improved jack it is evident that upon rotation of the main operating or drive shaft 28 that the driven shafts 26 and 27 will be operated in opposite directions and that the upper shaft will serve to lift the main rack bar 2O While the lower shaft 27 will serveto raise the casing 15, thus bringing about simultaneous movement of the casing and the main lifting rack bar.

From the foregoing description, it can be seen that we have provided an Vimproved jack of an exceptionally simple and durable construction which can be operated simply and efficiently with a minimum amount of energy.

Changes in details may be made without departing from the spirit or the scope of this invention, but:

What we claim as new is:

l. A jack comprising a base plate, a pair of spaced supporting rack bars, a casing slidably mounted on the rack bars, a lifting rack bar slidably mounted in the casing intermediate the first mentioned lifting rack casing between the first mentioned rack bars, A

gear housings formed on the easing, -upper and lower driven shafts rotatably mounted in the casing, a pinion carried by the upper shaft engaging and meshing with the lifting rack bar, a pair o-f pinions carried' by the lower shaft engaging and meshing with the supporting rack bars, worm wheels secured to the shafts and rotatably mounted in said gear housings, a drive shaft, and a worm carried by the drive shaft which meshes with said worm wheels.

In testimony whereof we aix our signa,- tures in presence of two witnesses.

Witnesses A. J. CA'rHow, EVELYN SMITH. 

